This has probably already been reported multiple times but I'm too much of a dumb American to find the search function in German.
I bolded the "any" in "any page" because I searched(googled) this problem and came up with some Chrome users saying "it's a bug with certain pages" which is a wrong statement. This is a bug that happens and does not go away. It doesn't happen with only certain pages but with all pages.
Again I'm sure this has been reported before, but I figured it's better to report than to leave it unreported and hope someone else reported it. I don't expect this to be fixed overnight, and I don't even expect a reply to this thread from the development team but I would like to take the time to thank the developers for this browser, I haven't clicked on Firefox(Fireslug) in a loooong time.
All the best to you and yours!